Device for charging and discharging heads of ray emitters

ABSTRACT

A device is provided for charging and discharging heads of ray emitters through the outlet for the cone of useful rays. The device has a source carrier with a radioactive element, a transporting container for the source carrier and a charging rod for moving the source carrier which provides protection against rays in its cross-sectional range. The device is particularly characterized in that the source carrier can be firmly held in the head of the ray emitter without moving and can be firmly coupled with the charging rod at the front side in the direction of movement, the source carrier carrying the radioactive element in the center of the coupling surface.

United States Patent [191 Scheininger et al.

DEVICE FOR CHARGING AND v DISCHARGING HEADS OF RAY EMITTERS lnventors: Ludwig Scheininger; Otto Nette,

both of Erlangen, Germany Assignee: Siemens Aktiengesellschaft,

Erlangen, Germany Filed: July 15, 1971 Appl. No.: 162,917

Foreign Application Priority Data Aug. 17, 1970 Germany 2040779 Int. Cl G2lh 5/00, G211 3/00 Field of Search 250/106 S, 108 R References Cited UNITED STATES PATENTS 7/1950 Strickland 250/106 S X Kaiser .l 250/106 S Untcrmyer; 250/l06 S Primary Examiner-Archie R. Borchelt Attorney-Agent, 0r Fir/ii Richards & Geier; V.

Alexander Scher 5 7 ABs TiiAc'r A device is provided for charging and discharging heads of ray emitters through the outlet for the cone of useful rays. The device has a source carrier with a radioactive element, a transporting container for the source carrier and a charging rod for moving the source carrier which provides protection against rays in its cross-sectional range. The device is particularly characterized in that the source carrier can be firmly held in the head of the ray emitter without moving and can be firmly coupled with the charging rod at the front side in the direction of movement, the source carrier carrying the radioactive element in the center of the coupling surface.

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PATENTED MAR 5 I874 ATT RNEY;

discharging heads of ray emitters through the outlet for.

the cone of the useful rays. The invention relates more particularly to a device of this type having a source carrier with a radioactive element, a transporting container for the source carrier and a shifting rod for moving the source carrier which provides protection against rays in its cross-sectional range.

Devices of this type are used internationally. The length of the cylindrically constructed source carrier is approximately equal to its diameter. The front side of the source carrier is provided with screw'threads for attachment to the head. Two bag-like holes are provided on the opposite front side on both sides of the radioactive element which can be brought into engagement with corresponding pins of a charging rod. The drawback of this construction is that this source carrier can be pushed only vertically into the head or again removed from the head. For that purpose the transporting container for the source. carrier must be pushed under the head. The transporting container can be then charged and discharged by means of a charging rod which shifts the transporting container from the bottom upwardly and must be operated from the bottom of the transporting container by a person lying on'the floor. Below the transporting container there is no room for the complete length of the rod, so that when the container is moved upwardly. additional extension pieces must be added to the rod to extend it successively, while when the container is moved downwardly these pieces must be removed in reversed sequence. This charging and discharging procedure is not only tiresome and complicated but also dangerous. By way of example, the source carrier can remain hanging in the loading channel during discharge of the head as the result of a small side shifting of the transporting container. Then it will be separated from the rod in a manner which cannot be controlled. During the hanging there is a direct ray emission from allsides into the space between the head and the container. This means that when a new coupling of the rod is carried out and the disturbance is eliminated, there is substantial dangerfor all persons operating in that room. If the hanging is not noticed and the container is shifted to one side the source carrier'with the radioactive element can drop upon the room floor and this can having most terrible consequences for all persons present in the room. The proper reinstatement of the source carrier cannot be carried out by means generally tal.

An object of the present invention is to eliminate these drawbacks of existing constructions.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the pres ent invention it was found desirable to arrange the source carrier so that it will be held firmly in the head of the ray emitter without moving and that it be firmly coupled with the shifting rod at the front side in the direction of movement, the radioactive element being carried in the center of the coupling surface. This arrangement completely avoids the possibility that the hanging of the source carrier in the loading passage will remain unnoticed. At the sametime the possibility is provided to charge and discharge the ray emitting head available in a hospi- 2 of the described type from the side as well. This also includes the possibility of operating with a one piece charging rod.

In accordance with the present invention a particularly safe construction is produced when the source carrier and at least that part of the charging rod which is directed toward the source carrier and is constructed as a so-called protective bolt, are shaped as massive cylinders with a cross-section adapted to the loading passage and have an axial length providing complete protection from the rays. Due to the absence of a slit leading to the radioactive element so called slit-leak ray emission is avoided which could otherwise take place along the guide of the charging rod at the closure of the charging passage for the transporting container. Thus it is possible to reduce requirements which are necessary to provide closures for the charging passage of the transporting container to provide safety against rays.

According to a particularly advantageous embodiment of the present invention, a sack-shaped hole is provided upon the circumference of the source carrier to prevent its turning and shifting in the head. A stop rod which is movably mounted in the rotary axle of the closure roller perpendicularly to the charging direction in the head, can be introduced into this hole so that the source carrier can be firmly connected with the charging rod to prevent rotation and shifting. This makes it possible to provide in a simple manner information from the extent of penetration of the stop rod about a secure locking of the source carrier in the head. Such secure locking of the source carrier provides at the same time a guaranty for the precisely reproduceable location of the source carrier in the closure roller of the ray emitting head.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing by way of example only, a preferred embodiment of the inventive idea.

In the drawing:

FIG. 1 is partly a side view and partly a section showing the source carrier and the charging rod. 1

FIG. 2 is partly a side view and partly a section illustrating the head of a ray emitting device and the transporting container at the beginning of the charging phase.

FIG. 3 is partly a top view and partly a section through the parts shown in FIG. 2 at the end of the charging phase.

The source carrier, 1 and the charging rod 2 are shown in FIG. 1. The charging rod 2 consists of a trunk 3 and a so-called protective bolt 4 which is screwed to the trunk. The bolt 4 and the source carrier 1 are made of massive cylindrical bodies and can be firmly interconnected with their front sides through a bayonet lock 5. The radioactive element 6 is fixed in a container 7 centrally upon that front side of the source carrier 1 which carries the bayonet lock 5. The lengths of the source carrier 1 and of the bolt 4 are so selected that the dose emission of the rays drops in axial direction to values permissible as far as protection against rays is concerned. A sack-shaped hole 9 extending perpendicularly to the axis 8 of the cylinder is provided upon the end of the source carrier 1 which is away from the radioactive element 6.

In FIG. 1 the trunk 3 is shown as being separated from the bolt 4 to better illustrate the firm connection of these two parts preventing their shifting and turning relatively to each other. The front side of the bolt 4 located opposite the bayonet lock 5 carries a central threaded hole as well as an excentrically located sack-shaped hole 11 for attaching the trunk 3. The

trunk 3 consists of an inner part 13 carrying a screw 12 and an outer rotatably mounted cylindrical cover 14 upon which is fixed a pin 15 fitting into the hole llof the bolt 4.

The operation of the charging and discharging of a ray emitting head 16 of a ray emitting apparatusis as follows, with reference to FIGS. 2 and 3:

The drawing shows a head 16 suspended upon two supporting arms 17 and 18 and swingable about an axis 19. During the charging operation the cover which normally limits the outlet channel 20 of the cone of the useful rays, is replaced by a guiding cylinder 21. A locking roller 22 is mounted within the head 16 and is rotatable about its symmetry axis 23 extending at right angles to the cone of useful rays. The roller 22 has a recess 24 for the source carrier 1. A bore 25 for a stop pin 26 extends in the symmetry axis 23 of the roller 22 from outside through the wall of the head 16 and up to the recess 24 for the source carrier 1. The outer surface of the head has a holder 27 for the pin 26. The head is provided with a short cylindrical flange 28 upon that side wherein the outlet passage for the cone of useful rays is located. A transporting container 29 for the source carrier 1 is fixed by an intermediate ring 30 to the flange 28 of the head during the charging operation. The transporting container 29 includes a charging passage 31 extending centrally through it. In this charging passage are movably mounted the bolt 4 and possibly the source carrier 1 firmly connected with the bolt. FIG. 2 shows the source carrier 1, the protecting bolt 4 and the charging trunk 3 as being connected with each other.

In order to charge or discharge the head, the cover is replaced by a guiding cylinder 21 having the same dimensions. Then the intermediate ring 30 is fixed to the transporting container 29 for the source carrier 1 and the transporting container 29 is screwed with the head 16 over this ring. The locking roller 22 of the head is then turned into the ray emitting position. In this position the recess 24 for the source carrier 1 is in alinement with the bore in the guiding cylinder 21 and also with the charging channel 31 of the transporting container 29 due to their connection through the intermediate ring 30. Now the source carrier 1 with the trunk 3 can be pushed through the charging passage 31 of the transporting container 29 and through the outlet passage 20 of the head 16 into the recess 24 of the locking roller 22. By introducing the pin 26 into the hole 9 of the source carrier 1 the carrier is stopped inside the roller 22 against shifting as well as against rotation. The bayonet lock 5 between the bolt 4 and the sourcebarrier 1 can be released by means of the trunk 3. By turning the roller 22 to the extent of 180 the source carrier is moved into the waiting position shown in FIG. 3 in which it is screened against rays. When the bolt 4 is pulled back in the transporting container 29, the latter can be removed without danger from the head and the guiding cylinder 21 can be again exchanged for a cover.

Due to the axial arrangement of the bore 25 the pin 26 does not prevent the rotation of the roller 22 from the waiting position to the ray emitting position and back. Since the bore 25 containing the pin is not directed toward the radioactive element 6, no direct slitleak radiation can pass through it, so that the provision of special ray protecting means is not necessary. By examining the position up to which the pin 26 can be pushed into the head 16, it is possible to determine whether the source carrier 1 is properly positioned and held in the roller 22.

During the entire charging and discharging procedures the source carrier 1 is firmly fixed and guided either at the trunk 3 or' at the roller 22 or at both. Thus the source carrier is always controlled. Due to the firm connection of the source carrier 1 with the bolt 4 and the trunk 3, the source carrier can be also pushed horizontally into the head 16 or pulled out of it. This makes it possible to use one piece charging rods. Finally the construction of the source carrier and of the protecting bolt as cylinders of corresponding lengths capable of being joined with a ray source located in between makes it possible to use simple transporting containers with a horizontal charging passage without special locking rollers.

Obviously it is possible to provide claw couplings 'or electrical couplings between the bolt 4 and the source carrier 1 and between the bolt 4 and the trunk 3 and to operate them independently from 'each other from the charging place. When such couplings are used which are operable in the shifting direction and which do not require the rotation of the bolt 4 or of the trunk 3 for closing or opening, it is sufficient to stop the source carrier 1 in the head 16 only in the shifting direction. The hole 9 can be replaced by an annular groove. In that case it is not absolutely necessary that the source carrier and the bolt should have a circular cross-section.

We claim:

1. A device for charging and discharging a ray emitter head, comprising a source carrier, means firmly holding said source carrier in said head, a charging rod comprising a bolt located adjacent said source carrier and having a surface adapted to be firmly coupled with a surface of said source carrier in the direction of movement, and a radioactive element carried in the middle of said surface of the source carrier, said source carrier and said bolt having the shape of massive cylinders having a cross-section adapted'to the charging passage and having a length providing complete axial ray protection.

2. A device in accordance with claim 1, wherein said means comprise a hole provided upon the circumference of said source carrier, a locking roller and a stop pin adapted to be introduced into said hole and to be movable perpendicularly to the charging direction of said head and in the rotary direction of said locking roller, whereby said source carrier is connected with said charging rod to prevent its rotary and shifting movements.

3. A device in accordance with claim 2, wherein said charging rod comprises a trunk, said means comprising a coupling joining said trunk with said bolt to prevent their shifting and rotary movements and adapted to separate said trunk from said bolt. 

1. A device for charging and discharging a ray emitter head, comprising a source carrier, means firmly holding said source carrier in said head, a charging rod comprising a bolt located adjacent said source carrier and having a surface adapted to be firmly coupled with a surface of said source carrier in the direction of movement, and a radioactive element carried in the middle of said surface of the source carrier, said source carrier and said bolt having the shape of massive cylinders having a cross-section adapted to the charging passage and having a length providing complete axial ray protection.
 2. A device in accordance with claim 1, wherein said means comprise a hole provided upon the circumference of said source carrier, a locking roller and a stop pin adapted to be introduced into said hole and to be movable perpendicularly to the charging direction of said head and in the rotary direction of said locking roller, whereby said source carrier is connected with said charging rod to prevent its rotary and shifting movements.
 3. A device in accordance with claim 2, wherein said charging rod comprises a trunk, said means comprising a coupling joining said trunk with said bolt to prevent their shifting and rotary movements and adapted to separate said trunk from said bolt. 